The technology works well, but getting it to the market remains a struggle

Scientists have tinkered with them for longer than Strom Thurmond has paced the Senate floor. They can mitigate the uncertainties of oil prices on one hand and the threat of climate change on the other. They will be clean and quiet and cheap and won't take up much space in the backyard or basement or wherever you care to put a refrigerator-size box that isn't a refrigerator but can keep one cold. They will bring light to America's moonlit homesteads, pollutionless cars to its highways and stealth weed whackers to its suburbs. They are hydrogen-powered fuel cells, coming soon to an...